Saw-tooth



(No Model v KRIEGBR.

SA-W TOOTH.

NO. 292 .659. Patnted Jan. 29 1884.

N. PETERS. Plwln-Lilhngmph UNITED STATES PATENT Orrrcn.

- lumbus, in the county of Franklin and State .semicircular recess, intowhich enters a projection of similar form on the saw-blade O, the

vacant between, but the projection from the eAw-TooTH.

SPECIFICATION forming part of Letters Patent No. 292,659,dated January29, 1884,

Application filed October 5, 1883. (No modcln To aZZ whom it may concerlBe it known that 1, ANDREW KRIEGER, a citizen of the United States,residing at Coof Ohio, have invented certain new and useful Improvementsin Detachable Saw-Teeth, of which the following is a specification,reference being had therein to the accompanying drawings.

My invention consists of an improvement in detachable saw-teeth. Asaw-tooth of a pcculiar form and a clamping-piece to hold it areinsertedin a suitable recess in a circularsaw plate, as will be fullydescribed hereinafter. y The accompanying drawings represent myinvention.

Figures 1 and 2 are side elevations, showing the manner of attaching theteeth to the sawplate. Figs. 3 and 4 are detailed views.

The tooth A, made of bar-steel, is forged in a die. Its cu'tting-edgeisin the formof a V, the under side of which is the continuation of thesection of a circle, in which the clampingpiece B is held. In thebackgof the tooth is a recessandprojectionformingaball-joint,c,and fromthis, which is about one-half of the whole length .of the tooth, theback extends in a straight line, 4, to the foot e. This straight line cland foot 0 of the tooth are under ordinary circumstances not in, contactwith the saw-plate 0, there being a narrow space left saw-plate in theball-joint c and the clamping-piece B press against the toothfromopposite sides. At the edge of the tooth is a V-shaped tongue, thatenters a groove in the upper end of the clamping-piece, and in thesemicircular recess of the tooth is a groove for a tongue on thesaw-plate to enter. The circumference of the clamping-piece is dividedinto sections of two concentric circles, to and b, of differentdiameters. The larger .of them, a, bearing against the tooth, is joinedby a straight line, f, to the smaller one, I). The upper and centralparts of the clamping-piece B are removed, leaving enough of thematerial to resist a strong pressure. In the edge of thecircumference ofthe clamping piece is a groove, and on the edge of the saw-plate is anecessary to make this allowance, since it is very difficult to maketeeth of exactly the same dimensions, without which they could not beplacedin the recess. It also allows them to adjust themselves to thepressure of the clamping-piece when turned into its place. The abutmentunder the foot 6 of the tooth serves as a check in case the cutting-edgeshould run against iron or other hard substances, by which it might beforced out of the ball-joint.

Instead of breaking the clamping-piece or the point of the saw-plate,the tooth itself would break at the ball-jointits weakest placeand fallto the ground without injuring the saw. The ball-joint offers theadvantage of the tooth being readily inserted, and of great 1y reducingthe friction between the saw-plate and the clamping-piece, when thelatter is being turned to fasten or loosen the tooth. The tooth is firstheld in position in its recess in the saw-plate; then the tongue on theedge of the tooth is placed in the groove of section a of clamping-pieceB, so that the heel on the straight line f, by which the two circles toand b are connected, stands under the cutting edge of the tooth, asshown in Fig. 1. If, now,

- yielding to the pressure, which is constantly increasing, turns upwardin the ball-joint as long as the pressure is exerted above the center ofthe joint, the foot of thetooth sliding forward out of its recess. Bycontinuing to turn the clamping-piece downward, as soon as the heel ofthe section a arrives on a line with the center of the joint, where itexerts the greatest pressure, the tooth returns to itsformer position,the foot moving back into its recess, and when the heel of theclamping-piece has arrived below the center of the joint, the pressuregradually diminishes until the clamping-piece reaches its seat.

From the foregoing it will be understood that the greatest pressureagainst the tooth is exerted opposite to the center of the ball-jointwhen the clamping-piece is turned into its recess, and again whenremoved from it. This pressure, increasing as soon as the clampingpiecebegins to be turned down or upward from its seat, holds it in place andlocks the tooth. XVhen in operation, the resistance of the material tobe sawed has a tendency to raise the point of the cutting-edge of thetooth, consequently to push out the foot, which, not being able to movein that direction, presses constantly against the clamping-piece,assisting thereby to hold it in its place.

Having thus described my invention, I claim 1. The combination of thesaw-plate, a re movable stw-tooth, and a clamping plate or device, theupper end of the tooth being rigidly clamped between the saw-plate andclamp, while, its lower end remains free, substantially as shown.

2. The combination of the sawplate O, having the projection c, and arecess formed by the lines d 0 just below it, the removable tooth A,having a recess in its rear edge to receive the projection r, and theclan'lping-plat-e B, the upper end of the tooth alone being clampedbetween the saw and clamping plates, while its lower end is separatedfrom the saw-plate, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

ANDRIHV KR-TEGER.

\Vi tnesses:

CYRUs HULIXo, J. R. Bowuma.

